One example, to which a conventional voice input method is applied to voice recognition, has been described in a patent document 1. This conventional system has an object by which a user can easily specify a cause for miss-recognition, and is a system by which, when voices used for voice recognition are analyzed, and a wrong factor obstructing the recognition is detected, the detection is feed backed to a user. As a feedback method, there have been a method, by which guidance is executed for a user, and a method by which voice input is controlled by adjusting a voice input gain on the side of the system, by approaching a microphone, by noise suppression, and the like. In a patent document 2, there has been described a method in which, when there is caused a failure in voice recognition in order to feedback a malfunction of a voice input to a user, the voice, during a voice detection section in which a voice recognition engine is used, is replayed, and is given to a user.
Moreover, in a Patent Document 3, there has been described a technology for sound-source-direction detection, and the technology can be applied as a partial element of the present invention. Moreover, in a Patent Document 4, there has been described a technology for noise reduction, and the technology can be applied as a partial element of the present invention. Moreover, in the Non-Patent Document 1, there has been described a technology for voice recognition, and the technology can be applied as a partial element of the present invention.
[Patent Document 1] Japanese Laid-Open Patent Publication No. 2003-330491;
[Patent Document 2] Japanese Laid-Open Patent Publication No. S61-094095;
[Patent Document 3] Japanese Patent Publication No. H07-022434;
[Patent Document 4] Japanese Laid-Open Patent Publication No. 2005-250397;
[Non-Patent Document 1] Kano, and other four writers: “Speech Recognition System” First Edition, p. 157-158, May 15, 2001, published by OHM ELECTRIC INC.